Wear-indicating resistors for thermal printhead
US8223181B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 24, 2009 |
| Grant date | Jul 17, 2012 |
| Priority date | — |
| Expiry date | Jan 10, 2031 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41J2/3353
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A thermal printhead includes a substrate, a nonconductive coating over the substrate, a number of heating elements disposed on the substrate, and one or more resistors at least partially disposed within the nonconductive coating. The heating elements cause thermochromic media to selectively darken in accordance with selective activation of the heating elements as the media moves in relation to the thermal printhead, to print a desired image on the media. The nonconductive coating protects the heating elements and wears away with usage of the printhead. The media comes into contact with the nonconductive coating during printing of the desired image on the media. The resistors indicate wear of the thermal printhead, and have electrical resistances that increase as the resistors are worn away in accordance with wearing away of the nonconductive coating.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.